Twitter has given birth to yet another inane “challenge” for those who like to prove themselves on social media. For the “belly button challenge,” which began on Chinese social media, teens reach an arm behind their back to try and touch their belly button. The point of the challenge, as takers see it, is to prove that you’re slim enough to reach your belly button.

In a time when our culture is becoming more body-positive, it’s a surprise and a shame to see thousands of people on social media posting pro-thin selfies. Huffington Post called the challenge “body shaming at its worst.”

The Atlantic comprised a list of reasons why it’s best we “Don’t Try the Belly Button Challenge.” As James Hamblin pointed out, the challenge actually tests shoulder flexibility, not fitness. Since your shoulders have the “greatest range of motion of any joint in the body,” you’re not proving much of anything (other than, perhaps, your viability in a contortionist circus sideshow).

Eating disorder activists are also speaking out for people to ignore the challenge. National Eating Disorder Association program director Claire Mysko told ABC News:

“Social media challenges like these can stoke comparison and body insecurity, especially for those struggling with disordered eating. We advocate for body positivity challenges, which are empowering and encourage self-expression, not self-criticism.”